Forests of Holderness. 287 



in the Humber, where the rise of the tide may be taken at 

 24 feet. How can we explain the growth of trees at the 

 level of half-tide ? The notion appears to be general amongst 

 geologists that phenomena of this kind require the admission 

 of local or general changes oflevel of the land and sea. That 

 such changes have often occurred is indisputable, and few 

 parts of the country have not experienced them. But in this 

 particular instance there seems no necessity for invoking any 

 such operation : what is known of the action of the sea on the 

 coast of Yorkshire and in the estuary of the Humber will give 

 us a more simple and more applicable theory. 



In order to see this, we have only to consider what would 

 be the effect upon the movement of the tide over the levels of 

 Holderness if its rampart of banks was removed. Undoubtedly 

 the tide would reach to distances and rise to heights inversely 

 proportional to the amount of the impediments which it had 

 to overcome. The line of high water is not necessarily a level 

 line, but, according to the form and depth and direction of 

 the channel up which the tidal impulse is felt, it may be a 

 rising line, as in some rivers, or a declining Wne, as in a system 

 of imperfectly connected meres or lakes branching off from 

 some limited tide stream. Now, remembering the descrip- 

 tion formerly given of the very intricate admixture of winding 

 hills and hollows in Holderness, we can easily see how, over 

 the tortuous, shallow, and often contracted course, at right 

 angles to its main stream in the Humber, the tide water should 

 be slowly and unequally propagated, so as to influence hardly 

 at all the interior hollows of the country. The length of time 

 during which the tide would flow, the distance which it could 

 reach, and the height which it might attain, would all be de- 

 pendent upon the configuration of the country, — as on theYar- 

 mouth coast the flow of the water is retarded and lowered 

 many feet by the shallow and intricate sand banks. 



9. Again, if the aperture for the tide to enter were more 

 contracted and further removed than at present, and if at the 

 same time the interior basins were larger, it is obvious that 

 the flow of the tide toward the shallow and intricate ramifica- 

 tions of these basins might be insensible, and thus hollows 

 might exist and be drained though their surface was below 

 the present tide level. Now it is well known that the whole 

 of the coast of Holderness is subject to a regular and progres- 

 sive annual waste, and that by this process the configuration 

 of the mouth of the Humber has been greatly changed: large 

 portions of land have been washed away both within and 

 without the Sourn Point, and from the opposite coast of Lin- 

 colnshire about Grimsby; and the cliffs of Paghill are only the 



